Make A Mark

React Native based mobile app experimenting with map rendering in apps.

APK for download - v0.1

App Demo

Storybook Demo

Instructions for dev setup

• yarn rn start will start the usual RN server for serving files in the debug mode.
• yarn storybook however serves the storybook mode, with all components shown independently in the storybook. Helpful for manual testing and independently operating on components.
• yarn android for building and installing a debug build to an attached Android device
• yarn lint . for running lint tests.
• The dev setup is dependent on the environment config file(.env) that contains configuration keys and secrets that the app needs. (Please get in touch with me for getting env secrets). Sample env file here.
• The app communicates to the API server using an agreed upon pre-shared access token, based on JWT.

Features and Considerations

• The app consists of the following features in the first version
  • Ability to view a map, with the usual map functions.
  • Ability to search addresses on the map and consequently mark them.
  • Ability to view all markers and cycle through them one by one.
  • Ability to remove a marker.
  • Server sync for storing coordinates store.
• Uses the Mapbox Maps API for rendering maps and geocoding.
• The code is structure in way that the Geocoder component is independent and reusable. That means not only can it be used at any other place without dependencies, all code dependent on the geocoding service is isolated so that it can be plugged out and replaced with anything else if needed.
• Since the app is all about maps and geocoding, the third party service is a clear single point of failure. This is understood and a possible way to work around this is to have a fallback UX devoid of the geocoding search(only map based). And have a fallback third party service in case the primary service doesn't work. None of them were easy enough for v1.
• The app assumes Germany as the default area of operation, limiting search results to Germany and the default map view to Germany.

Notes

• Android as the primary choice of platform for testing, purely for ease of sharing. The code, however, runs on both.
• Includes Storybook for manual testing of components.
• Given above, skips snapshot based unit-tests for components since all components are too simple and volatile for unit tests to provide high value.
• There is a pending PR for Redux integration but I intentionally stayed away from introducing Redux to the app. Especially when all the first-round features were limited to one container component and could be handled easily with component state.
• Storing just the coordinates for locations is probably an INCOMPLETE design given lack of geocoding knowhow. One coordinate might have several locations marked on it.
  • However, the geocoding service used advises against using any property value from their responses since they are volatile and can change even in a single API version. Using the id from the location objects from the maps service as identifiers for places was tried, but given away due to this constraint from the service.
  • On further research, I found that the Google Maps Geocoding service indeed mentions 'Place ID' as the unique identifier for a place in the Google Places database. As an immediate improvement, I'd change the API schema to store extra information other than the coordinates.

TODOs

With more time, would have done the following -

• Implement 'Delete Marker' functionality.
• Abstract out color literals to Color Palette library.
• Refactor forward-geocoding logic out from the Geocoder component.
• Would integrate react-redux, redux, redux-thunk and the usual before moving to the next set of features.
• Refactor out all geocoding service interactions to a service for better abstraction and isolation. This is not straightforward. Would lead to the Geocoder component getting coupled with a service and thus not easily reusable.
• Update the API design to store extra information other than a coordinate to uniquely identify a place. Could be a place ID but Mapbox mentions this can change, so it won't be enough at least with Mapbox.
• Deliberate on whether moving the Geocoding service to the backend makes sense. The provider gives a dedicated client-side JS library for Geocoding interactions. Moving that interaction to the backend would mean adding another API layer for relaying that communication to the client. Was out of the scope for v1 of the exercise.

Known Issues

• Due to multiple addresses on the same coordinate ( per the geocoding service), sometimes the address marked and address that shows might differ between sessions.
• Due to inaccuracies in coordinate decimal comparisons between storing and operating, sometimes the delete operation on the markers doesn't work well.
  • This is primarily because the coordinate is being stored as a decimal and the coordinate matching on the API server looks for an exact match, doesn't approximate comparison.
  • Another ideal way to work around this would be to communicate with Marker.id while operating on markers, this would eliminate the need for coordinate comparisons for retrieving markers.